Clinical trials suggest that Rosiglitazone ( Avandia ), a drug that helps control blood glucose levels, may also reduce blood pressure in people with type 2 diabetes.
According to the American Heart Association ( AHA ), patients with type 2 diabetes are two to four times more likely to develop cardiovascular disease.
In one study, combination therapy with Rosiglitazone and Metformin or a sulfonylurea demonstrated sustained reductions in blood pressure in people with type 2 diabetes compared to combination treatment with Metformin and a sulfonylurea. Hypertension, is a common risk factor for cardiovascular disease.
In a second study, in addition to reducing blood pressure, Rosiglitazone in combination with Metformin reduced microalbuminuria in patients with type 2 diabetes and microalbuminuria.
Microalbuminuria, a condition where small amounts of the protein albumin are found in urine, is a marker for cardiovascular disease in all people.
"Avandia is proven to be effective in improving blood glucose control in patients with type 2 diabetes," said George Bakris, at Rush University Medical Center in Chicago and lead study author of one of the studies. " These new data show that Avandia may also reduce blood pressure and microalbuminuria, which are associated with cardiovascular disease."
Eighteen million Americans are affected by diabetes. Type 2 diabetes accounts for 90-95% of all diagnosed diabetes cases. Of those Americans with diabetes, 11 million have high blood pressure.
In general, 64% of people with diabetes do not reach blood pressure goals, placing them at particularly high risk for cardiovascular disease.
According to the Centers for Disease Control and Prevention ( CDC ), cardiovascular disease is one of the leading causes of death in the United States and accounts for 65% of diabetes-related deaths.
Rosiglitazone improves blood pressure
A sub-study of the ongoing " Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycemia in Diabetes " ( RECORD ) trial was designed to evaluate the effects of Avandia in combination with Metformin or a sulfonylurea on 24-hour ambulatory blood pressure over a 12-month period.
The study included 759 people with type 2 diabetes, all of whom were inadequately controlled with Metformin or a sulfonylurea.
Those inadequately controlled on Metformin ( n=379 ) were randomized to receive the addition of sulfonylurea or Avandia.
Those inadequately controlled on a sulfonylurea ( n=380 ) were randomized to receive the addition of Metformin or Avandia.
Addition of Avandia resulted in a clinically and statistically greater mean reduction from baseline to 12 months in 24-hour ambulatory diastolic blood pressure, compared to addition of a sulfonylurea ( difference -2.02 mmHg ) or Metformin ( difference -3.17 mmHg ).
Similar patterns of changes were also observed for 24-hour ambulatory systolic blood pressure ( Metformin plus Avandia vs. Metformin plus a sulfonylurea: difference -2.73 mmHg; sulfonylurea plus Avandia vs. sulfonylurea plus Metformin: difference -2.64 mmHg ).
Rosiglitazone reduces blood pressure and microalbuminuria
A randomized, double blind, active-controlled study was conducted to assess the long-term effect of Rosiglitazone in reducing 24-hour ambulatory blood pressure and microalbuminuria [ as measured by urinary albumin/creatinine ratio ( UACR ) ] among people with type 2 diabetes and microalbuminuria.
Following a minimum of four weeks treatment with Metformin, 389 participants were randomized to the add-on treatment with Rosiglitazone or Glyburide for eight additional months.
Study medications were titrated to ensure comparable blood sugar control.
Avandia in combination with Metformin produced a statistically significant reduction in UACR from baseline ( 22.8% ).
However, the patient group treated with Glyburide and Metformin did not demonstrate a statistically significant reduction in UACR ( 7.1% ).
Additionally, Avandia in combination with Metformin produced a statistically greater reduction from baseline in 24-hour ambulatory systolic and diastolic blood pressure compared to treatment with Glyburide and Metformin ( difference -3.4 mmHg systolic and -2.5 mmHg diastolic, respectively ).
Treatment was generally well tolerated, with a similar incidence of adverse events, in both patient groups. Specifically, hypoglycemia was observed more frequently in the Glyburide plus Metformin group compared to the rosiglitazone plus metformin group ( 12.4% vs. 1.0%, respectively ).
Avandia may cause fluid retention or swelling which could lead to or worsen heart failure.
In combination with Insulin, Avandia may increase the risk of other heart problems.
Avandia is not recommended for patients with NYHA Class 3 and 4 cardiac status or active liver disease.
Also, blood tests to check for serious liver problems should be conducted before therapy and periodically thereafter.
Source: American Diabetes Association ( ADA ) 65th Annual Scientific Sessions, 2005